bash-completion: upgrade 2.12.0 -> 2.13.0

bash-completion: upgrade 2.12.0 -> 2.13.0

Changelog:
===========
### Features
------------
-Complete protocols for --proto-default
-Add completion for netconf subcommand
-Complete commands for netns exec
-Complete help for unknown subcommands
-Complete ip link property
-Complete link types for address show
-Complete neigh show and flush
-Complete stats subcommand
-Create function to get link types
-add fallback 3rd party completion loader
-also suggest *.rss files

### Bug Fixes
--------------
-fix regression of unwanted trailing colons
-Complete addrlabel add/del properties
-Complete ip delete with type correctly
-Complete more variations of subcommands
-Complete netns attach subcommand
-Complete only relevant addrlabel subcmds
-Keep completing after -netns name
-Quote all instantiation of ip as "$1"
-Quote network namespace names
-include api-and-naming.md in dist

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>